(d) All of these

Explanation:

Liver is the largest organ in the body. It helps in digestion and removes waste products and worn-out cells from the blood. Liver performs many functions, like it forms and secretes bile that contains bile acids to aid in the intestinal absorption (taking in ) of fats and the fat-soluble vitamins as A, D, E, K and B₁₂. Hence, it stores vitamins as A, D, E, K and B₁₂.